JP2005219054A - Control method for coating amount profile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method for a coating amount automatic controller which controls coating amount profile of a web in a blade coater. <P>SOLUTION: A coating liquid 5 blown out from an applicator section 1 is applied onto the web 2 continuously travelling on a backing roll 3 and the applied coating liquid is adjusted to a required coating amount by pressing pressure of a blade 4. As an adjusting means in width direction coating amount profile of the blade coater with which coating is thus performed, operation amount of a coating amount adjusting block 6 is controlled according to a profile value calculated by multiplying a signal of coating amount sent from a BM meter 7 by a moving average. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a control method of a coating amount automatic adjusting device for controlling a coating amount profile of a web in a blade coater.

  As shown in FIG. 1, the blade coater is coated with the coating solution 5 blown from the applicator unit 1 on the web 2 continuously running on the backing roll 3, and the coated coating solution is required by the pressing pressure of the blade 4. This is a device that adjusts the amount of coating and applies it in many relatively high-speed areas where productivity is important. The line speed is operated at 1000 m / min or higher, and recently it is operated at 1500 m / min or higher. There are places that have been.

  Conventionally, when adjusting the coating amount profile of the web, the operator manually pushes and pulls the profile adjustment screw by an amount corresponding to the coating amount profile after viewing the profile screen of the BM meter on the coater unit. However, it is not easy to adjust the profile in the coater head having a width direction of 5 m or more, and it takes time and labor.

  Recently, a coating amount profile automatic control device that adjusts the coating amount profile in conjunction with the BM meter has been developed. However, the stability of the coating amount in the interlock control of the BM meter, moisture meter, latex meter, etc. There are still insufficient points. As control methods for stabilizing the coating amount, methods such as JP-A-7-265774, JP-A-8-207121, and JP-A-8-299881 have been devised. It is easy to reflect this variation, and further suppression of variation is necessary. In particular, with respect to the profile of the edge portion of the web, it is difficult to correct the coating amount simply by moving the adjustment block corresponding to the edge portion. Pushing and pulling will cause a loss of paper such as uneven coating and streaks.

  The signal corresponding to the coating amount of the BM meter is usually displayed as a profile of the coating amount by measuring the width direction of the web at intervals of about 5 cm. However, the deviation of the measuring system itself and the variation in the web flow direction are large. For this reason, the displayed profiles vary greatly.

  In addition, since the profile automatic control device moves the adjustment block corresponding to the application amount signal of the BM meter, the variation of the BM meter is reflected in the movement amount of the adjustment block as it is, and the adjacent adjustment block moves in the opposite direction and is adjacent. Since the adjustment block operates every time the control of the adjustment block stops or is controlled by the limit, the profile may be destabilized. In addition, the variation of the adjustment block moved by the interlocking control with the BM meter also affects the blade tip pressure distribution or wear, etc., leading to increased blade loss due to early blade wear and unstable coating amount. It was connected.

  The present invention relates to a blade coater that applies a coating liquid blown from an applicator section to a web that runs continuously on a backing roll, and adjusts the applied coating liquid to a required coating amount by the pressing pressure of the blade. As a means for adjusting the width direction coating amount profile, a coating amount profile for controlling the operation amount of the coating amount adjustment block with a profile value calculated by multiplying the width direction profile signal of the coating amount sent from the BM meter by a moving average It is a control method.

  When the coating amount profile control device is used in the blade coater, the coating amount control of the web edge portion becomes easy, the operation of the adjustment block becomes smooth, and the profile in the width direction is stabilized.

  The present invention will be described in more detail with reference to examples.

Example 1
In the blade coater, the coating amount adjustment block 6 is located on the opposite side of the backing roll 3 through the web 2, and the interval between the adjustment blocks is generally 5 to 10 cm, but in the present invention the interval is 5 cm. I used one. Further, the stroke of pushing and pulling the adjustment block is generally within 5 cm in the front and rear, but there is also a device having a large stroke of about 10 cm in the front and rear.

  In many cases, the line speed of the blade coater is 1000 m / min or more for the bevel coating method and 600 m / min or more for the vent coating method, but recently, the speed increases and the bevel coating method is 1500 m / min or more. The operation case is not uncommon. The present invention is not particularly limited to speed, coating method, coating amount, and coating liquid property, and can be used in any case.

  In addition, the BM meter 7 is used as the measurement system in the present invention, but any measuring instrument can be used as long as it is an on-line instrument such as a moisture meter and a latex meter that can measure the coating amount in the width direction of the web at a constant interval.

  The application amount measurement signal from the BM meter is transmitted to the control computer. In this case, generally, when an existing BM meter is used, a signal subjected to smoothing processing is transmitted as shown in Equation 1. In the present invention, data without a smoothing coefficient, that is, a value in the case of SF = 1 in the mathematical formula is used. However, there is no problem even if data having a smoothing coefficient processed with an arbitrary value is used.

(Equation 1)
d2 = SF × d2old + (SF−1) × d1
d2old: coating amount before smoothing processing d2: coating amount after smoothing processing d1: coating amount after smoothing processing one time before the current SF: smoothing coefficient

  The coating amount data taken into the control computer is obtained by calculating the difference with respect to a certain target coating amount (setting value) by Formula 2, and calculating the push-pull of the corresponding adjustment block by Formula 3 again. The operation amount is transmitted to the drive motor that moves each adjustment block corresponding to the position, and the application amount is adjusted at a constant cycle.

(Equation 2)
dCDn = dPVn−dSVn
dPV: Current coating amount dSV: Target coating amount (set value)
dCD: Difference in coating amount n: Arbitrary

(Equation 3)
Ln = A × dCDn + B
dCD: coating amount difference value L: adjustment block movement amount A: coefficient B: coefficient n: arbitrary

  The signal of the coating amount transmitted from the BM meter is at intervals of 5 cm in many cases, but the solid line part in FIG. 2 shows that there are many variations due to the deviation of the measuring meter or the fluctuation of the web flow direction. Conventionally, the control of the adjustment block has been performed on the profile data, but the present invention performs an operation by multiplying this signal by a moving average according to Equation 4.

(Equation 4)
A _m = (a _mp + a _{m-p + 1} + a _{m-p + 2} ... + A _m ) / p
A: Application amount after calculation a: BM meter transmission application amount p: Number of moving average points m: Sign of arbitrary position

  FIG. 2 shows the data obtained after the calculation obtained by Expression 4, and the dotted line portion in FIG. 2 shows that the present invention performs push-pull of the adjustment block according to Expression 5 for this profile data.

(Equation 5)
Lm = S × Am + T
A: Application amount after calculation L: Adjustment block movement amount S: Coefficient T: Coefficient m: Sign of arbitrary position

  The amount of movement of the adjustment block as a result of the adjustment block being pushed and pulled by means of the present invention is shown in FIG. 3 (2). The conventional adjustment block is directly operated on the profile data transmitted from the BM meter. Compared with the result of the method ((1) in FIG. 3), the movement of the adjustment block was smooth, and there was no state in which adjacent adjustment blocks interfered with each other, so that stable application was possible. As for the moving average score, an average of about 5 points is most preferable, but there is no problem if the moving average score is in the range of about 3 to 8 points depending on the situation.

Schematic of the blade coater. The graph which shows the coating amount profile after implementing the calculation process of this invention to the coating amount profile transmitted from BM meter, and this coating amount profile. The graph which shows the moving amount of the adjustment block by the coating amount profile transmitted from a BM meter, and the moving amount of the adjustment block by the coating amount profile after performing the arithmetic processing of this invention to this coating amount profile. (1) The movement of the adjustment block when the adjustment block is adjusted according to the profile transmitted from the BM meter. (2) The movement of the adjustment block when the adjustment block is adjusted by a profile obtained by multiplying the profile transmitted from the BM meter by the moving average.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Applicator part 2 Web 3 Backing roll 4 Blade 5 Coating liquid 6 Adjustment block 7 BM meter 8 Drive motor

Claims (1)

  A blade for applying the coating liquid 5 blown from the applicator unit 1 to the web 2 that runs continuously on the backing roll 3, and adjusting the applied coating liquid to a required coating amount by the pressing force of the blade 4. As an adjustment means for the coater width direction coating amount profile, the operation amount of the coating amount adjustment block 6 is controlled by a profile value calculated by multiplying the width direction profile signal of the coating amount sent from the BM meter 7 by a moving average. Application amount profile control method.

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